Brown spots and brown tips

Most Likely Causes: 1. Nutrient Burn (brown tips on many leaves) Common in autoflowers, which are more sensitive to nutrients. Caused by overfeeding, especially with synthetic nutrients or "hot" soil. Signs: Leaf tips turn brown and curl slightly. Sometimes edges crisp up. Fix: Flush with pH-balanced water (6.2–6.8). Cut back nutrient concentration to ¼–½ of the recommended dose. --- 2. Calcium Deficiency (brown spots on older leaves) Especially common in soil grows without cal-mag supplements. Signs: Rusty or brown spots on older leaves, sometimes with weak stems or leaf edges curling up. Fix: Add a calcium-magnesium supplement (Cal-Mag). Ensure pH is stable (soil sweet spot is ~6.3–6.8) so calcium is available. --- 3. pH Imbalance Nutrient lockout from improper pH can mimic deficiency symptoms even if nutrients are present. Check your water runoff pH. If it’s below 6.2 or above 7.0, fix that first. --- Less Likely, But Possible: Potassium deficiency: Brown edges/spots, especially on older leaves. Light burn: If the top leaves are browning while others are fine, your grow light might be too close. --- What You Should Do Now: 1. Check pH of your water going in and runoff. 2. Flush if nutrient burn is suspected. 3. Add Cal-Mag if you haven’t used it. 4. Reduce feeding strength and watch for improvements over the next few days.